The latest Dropbox experimental version adds AppIndicator support as well as finally allows Linux users to change the notification area icon. The customizable icons may have been added in an older experimental Dropbox build because there isn't anything related to this in the changelog, but only now I've noticed it.

Here is the complete list of changes in the latest Dropbox experimental 0.8.55:

- Yet another tray menu reorganization.- New Ubuntu Application Indicator support (ubuntu versions 10.4 and higher)- Fixed regression on Windows that would unnecessarily ask for firewall permissions.- Fixed regression on Mac that would prevent startup. (stuck on Starting...)- Fixed rare sync bug that would require a restart to force an upload.- Other small fixes.

To upgrade to the latest Dropbox experimental (presuming you already have Dropbox installed):

You can also manually download the latest Dropbox experimental from HERE.

Dropbox notification area (tray) icons

If you want to change the icons, navigate to /home/your_username/.dropbox-dist/icons or paste this in a terminal to open the folder

nautilus ~/.dropbox-dist/icons

You can find some interesting icons HERE (but they are not for the notification area).

I've cropped some of the icons in the .svg file above (so all credits go to domore) to use in the notification area and uploaded a package which you can download from HERE. To use them, go to the Dropbox icon folder I was telling you about above, back up the original icons and then replace them with the newly downloaded icons.